Can You Charge A 16v Battery With A 12v Charger. 12 volts is too low to fully charge a 12 volt lead acid battery. But it is VERY easy to overcharge the battery I know as I tried a few times and it is VERY easy to not get full charge afterword because the absorption faze is impossible.
At night time the battery is at about 128-131V fully charged. The 16v adapter would raise the voltage too high and could cause damage. NO you cannot charge your 12V AGM battery directly with a 19V Laptop power supply.
Your 12v adapter would only be able to raise the battery voltage to 12v but to charge a car battery fully you would need to raise the voltage to 138v.
Unless you had a multirail charger. Consequently as long as the voltage applied to the cigarette lighter is more than the battery voltage you can push energy into the battery. The charger for the laptop batteries are inside the laptop. NO you cannot charge your 12V AGM battery directly with a 19V Laptop power supply.
